Learning to Protect
by Talon of soaring Eagle
Summary: His expression held nothing but curiosity when he pushed those giant leaves apart, eyes widening when he located the source of the distressed whimpering. Eyes still brimming with tears, a pair of equally curious eyes looked him over before a toothless grin split its little face. What was a baby doing out here in the jungle! AU Baby!Luffy


**A/n:** Heyoo! Alright FluffWithoutPlot abound! Just saying but Ace would probably be about seven, any age he was capable of taking out a king tiger with Sabo. This... is really freaking long by my standards... I dunno, have you ever imagined a single scene and you go "Aww I wanna write that" and then it becomes this... this thirty hundred word beauty! Luffy is a month old baby :3 there's a timeskip near the end, don't worry I stated it clearly- I think. OH GOD THIS IS GONNA GO HORRIBLY WRONG-

Now, without further ado, I present you with swearwords and intense mood swinging from the darling of this fandom! (that kid needs help)

 **Warnings:** Woah! For once there is no gore! Hurrah for me! Well to make up for that I included a whole metric shit ton of cursewords. Whoops, slip of the hand...

 **Disclaimer:** I is not own One Piece :DD

 **0o0o0o0**

Learning to Protect

0o0o0o0

The jungle air was dense, insects chirping and wind blowing around the giant leaves, stirring them into a rustling clamor.

Ace didn't pay attention to any of that, pushing apart the annoyingly large ferns on the ground to reach his goal. Finally seeing the source of the whimpering, his eyes widened. It was just a child, not even that, it was an infant in all its chubby, pathetic glory.

The thing instantly stopped crying as soon as it opened its too wide and innocent soft eyes, sticking its awed gaze onto Ace. Filthy, ragged Ace who never had a look of such wonderment bestowed upon him.

The boy blinked, almost taking a step back but he stiffened when the infant made a crooning noise, raising it's pudgy baby hands to grasp at him. Ace hesitantly approached, forehead creasing in worry when he realized something wrong. It wasn't packed full of baby fat like he assumed it was, those twig like arms were way too scrawny. He crouched down, pulling back the eye searingly red towel that was wrapped around it.

The boy licked his suddenly dry lips when he saw the clear line of tiny ribs against his skin, giving the baby the look of a minuscule skeleton. If he didn't know better he'd say it had been left here for at least a day, all alone. It was a wonder no predators had killed and eaten it.

Ace stiffened when he caught the sound of creaking wood.

Looks like he spoke too soon.

The boy swept the infant up in his arms and leaped to the side just in time for sharp fangs and claws to barely graze him. Heart pounding in terror of the gigantic leopard that had overshot them and was currently whipping around for a second try, he hugged the baby tight to his chest and ran like hell.

The baby seemed to understand just how deep in shit they were because for once it shut up, a tiny quivering bundle that clung hard to his shirt and hindered his movements just as much as his own short legs did. He was at a huge disadvantage here, the only thing he held over the stronger, faster big cat was the ability to fit into little nooks and crannies.

As soon as he spotted one, the very hungry cat hot on their heels, he dived into it, making sure the baby wasn't going to be squished under him before he squeezed into the furthest corner of the hollow den within the big roots to escape the claws being driven into the ground right outside. His heart nearly stopped when the leopard started tearing at the root riddled earth, praying to whatever higher being that he didn't believe in out there to not give the cat the strength for this hunt and just let them be.

The baby buried its face in his chest and whimpered, which only fueled the leopard's hungry growls. The claws retracted from the entrance of their little den and Ace allowed himself to open one eye, staring at the open air that was left behind.

 _SC-RCH!_

The loud noise made the baby scream in terror and start wailing. Ace's eyes widened in horror when the thunderous scrapes didn't stop. The cat was trying to tip the tree to widen the hole and once it did they were goners.

The dirt showered over them as the massive roots were pulled out the ground and the five year old caught a glint of deadly sharp teeth. Ace bolted, pumping his legs as fast as they would go even as he heard that predatory growl _right behind them_. He leaped over a log only to skid to a halt in front of a tall, tall rocky face.

Shit.

The leopard slowed back down to a stalk, it's yellow eyes glinting with victory as it stalked towards them. The baby looked up at him, big black eyes teary and looking at him like Ace was going to _save it_. The whole mess was its fault! There was nothing stopping him from dropping it and running. Ace narrowed his eyes and knelt, placing the tiny bundle on the earth, stood back up, and dashed off.

Straight towards the leopard.

He gave a roar of his own as he pulled back his fist, ready to let it fly.

He nearly tripped over himself, startled, when the big cat suddenly got blasted to the side, slamming hard into a rock with a flick of its tail. A hand grabbed the scruff of his shirt and dragged him off.

"Are you insane?! Or just stupid?!" A voice yelled, starting him out of his stupor.

Usually he would be kicking the unlucky someone's ass for saying that but at the moment the only thing on his mind was,"The baby!"

"Yeah yeah I got him, your little brother or something?"

Ace snatched the sniffling, hiccuping bundle from the other boy and hugged him to his chest, feeling reassured by the tight grip around his shirt. Because it meant none of them had died. He wasn't sure how the stranger had did it, but suddenly they were out of the forest and hiding in an unholy large pile of scrap metal. While holding a crying baby to his chest he cast a curious eye over the other.

He caught a glimpse woolly looking blond hair before the boy pulled a dark blue top hat back over his head, staring back at him with an equally curious gaze. He wore clothes that looked ratty but were, in comparison to his, regal. The boy was dressed in dark blue, complete with the leather gloves and a metal pipe gripped lightly in his hand.

"What? Never seen another human being before?" He joked and Ace felt like smacking him over the head, never mind that this guy just saved their asses.

"I'll be going, thanks for the save," he said in a semblance of politeness and shifted his hold on the baby to leave.

"Hold up!" The blond waved his arms in the air, effectively halting him,"My name's Sabo, what's yours?" The boy figured telling him wouldn't do any harm but as soon as he did he was stopped again. "And your brother?"

"He's not my brother," Ace snapped, though he held the little thing closer when it gave another hiccup. By then it was asleep, snoring softly into his shoulder. Almost unconsciously, the older boy swept off a bit of dirt that had found its way onto his forehead, a fond look crossing his face.

"If he's not your brother then what is he?" Sabo asked with a smirk on his face,"You just found him in the woods?"

"As a matter of fact, I did. Can I go now?" Ace felt the remnants of his patience wither away, annoyed at his idiotic savior.

"Geez man, I'm just trying to make a friend, it's been kind of lonely out here-"

"Oh boohoo, I'm leaving," Ace stalked off, shoving the metal pipe out of his way to exit the cubbyhole.

Behind him, Sabo sighed and sat back down on a crate. He fingered the brim of his hat, looking up and went over the conversation with the weirdo he'd just met. Hopefully he's see them again sometime, and hopefully the older boy, Ace, would have calmed down enough by then to have an actual conversation with.

0o0o0o0

Ace looked at the cooked crocodile meat he held in one hand, then looked towards the eagerly awaiting bundle that had crawled its way towards him.

 _/His name is Luffy, take care of him./_

The note had said, and it disgusted Ace so much that he threw the thing into the fire straight after reading it. What kind of scum would leave a defenseless baby in a fucking jungle of all places. Probably some sick maniac. He was tempted to rename his little adoptee just because anyone that was revolting enough to do that didn't deserve to name such a pure thing, but then he realized that whatever else didn't fit well with the infant, that name did, very well. Also he was bad at naming things, and he really didn't want to screw up anything else in the baby's life for him.

But now he faced the dilemma of feeding little Luffy.

Ace scooped the baby up and placed him in his lap, putting one finger in the his mouth to check his teeth. He got bitten, that wasn't surprising, but it was close enough to what he was aiming for. The baby had no strength in his little jaws, maybe they had the potential to grow strong, maybe one day he could even handle the thick bones of a bear, but right now what weak little Luffy needed was some nice mushy substance to swallow easily.

Ace looked back at the meat in his hand, then once again to little Luffy gnawing on his finger.

 _You're weak and a crybaby, but right now you're allowed to be, and I can't just leave you because you'll die. I hate crybabies, but I don't think I can hate you._

He tore a chunk of meat off with his teeth and started chewing, a flush on his face when he really thought about what he was going to do. Well it really wasn't that strange, he saw birds do it all the time. If they could, then he could too.

Ace grimaced, spat out some of the gross wet sticky mush he had produced into his hand and looked at Luffy's shining eyes again.

 _For the baby_ , he thought to himself, grimacing further when he brought it close to Luffy's mouth and plopped the mush in, using that chance to yank his finger out. His face turned slightly green when the baby happily 'chewed' and swallowed it, making a soft noise that just begged for more.

A shudder running up his spine, Ace tore another strip of meat off the chunk he held and begin chewing.

0o0o0o0

Ace rummaged around in the pile, yanking out a shiny item. He grinned when he saw that it had a fine silvery sheen, probably worth a bit, and chucked it into the sack he was dragging around.

"Hey!" He heard a familiar voice call out to him and he turned to face the figure with a scowl. Sabo stood there with his hands on his hips, still grasping that metal pipe, and a grin on his lips,"Glad to see you around again!"

"Screw off," Ace turned back to his scavenger hunt, determined not to let anything distract him. He needed to get enough money to buy some milk so that he didn't have to mama bird Luffy again. Once was enough for the young boy, though his charge seemed to like it.

Sabo on the other hand was disappointed that rude seemed to be Ace's default personality and gave up on him being civil for once. Guess he'd have to work with this mess. "What're you doing? Planning to sell some of that?"

"Oh, no, that's ridiculous," Ace growled,"I'm planning to feed this metal to Luffy, duh."

"Luffy huh, that's a cute name." The other boy was still smiling, though an irritated prickle was beginning to crawl up Ace's shoulders. No matter what he did it didn't ever seemed to manage driving this idiot away. "Seriously though, you planning to buy something with all that cash?"

Ace didn't answer, preferring to give him the cold shoulder if nothing else worked.

It seemed to be working, until he felt something fall into his bag. He turned a cold glare to the other,"What the fuck are you doing?"

"Just helping out," Sabo shrugged, already going back to digging,"you seem desperate, and milk is expensive nowadays."

"How did you- argh! Just leave okay? I don't need your help!" The sentence ended in a shout and he was so used to the blond just shrugging off whatever crap he threw at him that he was actually surprised when an accusing finger jabbed into his chest.

Sabo's eyes were narrowed dangerously, his face set in a frown,"Look here stupid, you need help, I'm giving it to you, the least you can do is shut up and take it like a man."

"A man?" Ace scoffed,"Like one would need your pansy ass help, rich boy."

The insult had hit home, or at least close, because Sabo bared his teeth and turned away. Ace's lips peeled back in a grin, but it was humorless. He resumed his rooting around but a few seconds later was surprised to hear someone else put something in his bag again, but this time a bit more violently.

"What? Haven't got enough?" He sneered at Sabo and the boy levelled an equally, if not more, intense glare at him.

"I'm doing it for Luffy, asshole. No matter what your obviously retarded head might think, one person isn't gonna be able to provide for a month old baby, and especially not with that attitude."

Ace opened his mouth to retort but the blond had already stalked off to a further location. For a moment the boy just examined his unwanted partner, watching the way he threw himself into the work, expertly sorting through the trash to pull out something that might be worth a few bucks. He shook his head and turned back to his pile, trying to place the wave of emotion he felt just now.

He felt... Warm... Like when Luffy first smiled at him, reaching out to grab his hand.

The next time Sabo stomped over to load his pile of items into the steadily growing sack, he could've sworn he heard a mumbled 'thanks' coming from the direction of the black haired boy that crouched a few meters away, face turned away from him as he determinedly stuck his hands into piles of garbage. Instead of replying, the blond returned the sentiment with a smile. Though Ace couldn't hear that smile, he did hear how Sabo's footsteps had lightened considerably.

Between them they earned about two hundred beli worth of scrap metal and that was easily enough for a month's supply of powdered formula. For a normal baby that was.

Ace learned quick, the next day the two were busy picking scrap metal again, their supply already halfway depleted.

0o0o0o0

Luffy was so completely and utterly useless that sometimes Ace wondered why he even bothered to take care of him. Then he would open his soft black eyes and croon something that sounded a lot like 'Esh' and his heart would melt all over again. The older boy bit his lip, holding back a fond smile, before giving in to it and grabbing the little thing to hold it close, feeling delightfully pudgy hands encircle his neck and a happy squeal being let out into his chest.

He heard a snicker sound out from the other side of the cavern where Sabo was mixing hot water and powder into a hard earned baby bottle with a twig that he _hoped_ was clean. Because if baby Luffy was going to get poisoned by something stupid like that he was going to kick the other boy's ass to the moon and back. At the moment he just gave him a halfhearted scowl, it was hard to form a proper one with Luffy nuzzling him like that, and got a stuck out tongue in return.

"Here's the milk, mama hen," Sabo sniggered, handing him the bottle. Ace cringed, thinking back to the time he _didn't_ have the bottle and had to resort to other... Highly unorthodox methods of feeding. He looked down at little Luffy getting drool on his shirt and shoved the dribbling bundle into Sabo's hands.

"You feed him," he said curtly. Though a part of him was screaming to not let anyone else touch his Luffy, a more rational part of him pointed out that the other boy obviously only wanted to help and was not going to start harming Luffy in any way right now. And if he was going to insist on helping out, he needed to have a bit of bonding time with the baby anyway.

Sabo fumbled with the infant for a second, which made Ace frown, before letting him settle in his unfamiliar arms. Luffy seemed happy enough to adjust, finally noticing the bottle he held and pawing at it with a soft 'Boh!' The black haired boy watched how the blond sat down, cradling Luffy in his lap, like he himself did so many times before, and support his head to feed him better. The baby wrapped both hands around the warm glass of the bottle and begin sucking eagerly on the rubber teat. Satisfied, Ace slipped out of the little cavern, leaving his (dare he say) new friend with his trust.

0o0o0o0

He heard some slurred mumbling coming from the pile of animal skins they had managed to collect, sitting up sleepily to approach the noise. Sabo was already hovering over the baby, face alight with curiosity while Ace's was just grumpy sleep residual.

"What is it Luffy?" The blond grinned encouragingly, holding the tiny hand and squeezing it. Said baby's face was scrunched up in concentration, his fingers and toes twitching as he went,"SSssSSssss..."

"Is that your snake impression?" Ace asked, unimpressed, while his friend just laughed.

"Doing a good job so far," he stroked his bigger fingers over Luffy's hand. The infant however stuck his tongue out and blew a very slobbery raspberry at them. Ace winced in disgust, wiping off some drool that had gotten on his face while Sabo just chuckled, that bastard.

"Boh!" Luffy cried, waving both arms to his left, where Sabo was kneeling. Both their faces lit up in surprise when Luffy went,"Sssssssahboh! Sabo!"

The blond looked positively delighted. He clapped his hands together and went,"You did it!" Like some overexcited dumbass. He _squealed_ for god's sake! Ace himself felt a flutter of something in his chest and it twitched his lips up in a grin, not the nice kind. Why did Sabo get the first word treatment and not him? He was the one that found Luffy. Well he didn't care, if the kid wanted to be like that, ungrateful brat, he could go and cuddle Sabo instead. No more hugs from Ace, nuh-uh.

"Why're you looking at me like that?" The blond laughed nervously, backing off slightly. Ace lowered his glare onto Luffy and simply huffed.

The baby giggled at his face and Ace felt any bad emotion that had been plaguing him for the entirety of his life wither and die. He couldn't stay mad at anyone as long as Luffy had a smile on his cute little face. He was about a year old at this point, he had sprouted little black locks of hair, his appetite had _grown_ , enormously, and he just said his first word. But it was Sabo's name. Honestly he felt like screaming.

Instead he grabbed Luffy off the fluffy wolf pelt and cuddled him as warmly as he dared with Sabo watching.

The blond was watching them with an amused grin, opening his stupid mouth to point out the obviously obvious unnecessary uncalled for,"Say Ace... Are you jealous? Of me?"

There could only be one answer to that. "No."

"Are you sure? You seem to be pretty possessive suddenly-"

"I'm not jealous." Ace said again, coldly, as he turned away. Luffy was making happy, squeaky noises against his chest, so he could forget the other idiot in the cave for the time being.

"Wait a minute, _why_ are you even jealous? Luffy says your name all the time!"

At this Ace froze, turning back with a curious look,"You're shitting me."

"I shit you not," the blond looked way too smug for his own good,"did you seriously not notice?"

"When?"

"All the time! Like- listen to him now!"

Ace pulled the little thing off his chest and stared hard at him, grey eyes widening when he heard Luffy saying, it was slurred and garbled _**but**_ it was barely distinguishable from a regular garbled slur,"Ayss!" Which was 'Ace', his name! Luffy had been saying his name this whole time!

The boy was stabbed through in the heart with a feeling so blissfully crippling he couldn't help crying out a joyful,"Luffy!" And he gave the baby a big affectionate smack of a kiss right on the nose, those messy ones that made a 'mwah!' sound. He didn't even care that Sabo was making gagging sounds behind him because he was too busy being drowned in the waves of love Luffy had managed to entice out of him.

Sabo just watched his very moodily unstable friend swing the baby round and round, happy squeals filling the air, as he mumbled to himself,"I'm gonna get diabetes."

Even with his comment, the blond continued watching the two, eyes clouded with thoughtfulness. Ace settled Luffy on his boar pelt and tickled the baby's sensitive sides with his dancing fingers, causing him to shriek and squeal. With about a few months experience of dealing with him, Sabo figured the other boy wouldn't be the type to act this carefree on his own. His gaze strayed back down to the giggling, flailing infant and he hummed, finger tapping his chin. Sabo snapped his fingers loudly with an 'aha!', catching the attention of the two.

"Hiccup!" Luffy went and that teased a smile out of Ace before he composed himself.

"Some amazing revelation, Sabo?"

"Yeah!" He said brightly,"You guys are brothers!"

"I told you before-"

"Hiccup!"

"No! I mean we've sort of adopted Luffy already, since we're obviously taking care of him, and you're clearly not gonna tell him you're his father-" Ace wrinkled his nose distastefully ,"-so we're his brothers!"

"That's..." Now it was Ace's turn to have an epiphany, his face split in a wide grin,"Yes!" He turned to the little thing he was holding up under his arms, nuzzling his nose with his own,"You hear that Lu? Wanna be our lil' bro?"

"Hiccup!" Luffy replied enthusiastically and Sabo scooped the baby up from Ace's arms, flicking his little nose and smiling at his squeal.

It was gonna be tough raising a baby from scratch, especially in the midst of a forest with animals ranging anywhere from fifty to seventy times stronger than their natural counterparts, but Sabo knew Ace would have his full support. Whatever it took, the little guy would get his fair share of TLC.

"Hey Ace," Sabo said softly, the other boy was looking at him curiously, like the first time they had met, without the glaring suspicion,"we're gonna be the best big brothers ever."

The other boy grinned, showing off a bit of fang,"You bet we will."

0o0o0o0

 **A/n:** Kind of around the time Garp threw Ace into the jungle for his training(if Luffy got that I'm pretty sure Ace did too). Way before he was introduced to Dadan. If that literally thought up three seconds ago explanation isn't enough then have I mentioned that this is AU? XD I'm sorry I wrote this on a whim... If you're wondering why Ace has no pipe, Sabo handed one to him shortly after these events take place because resident mama hen noticed that it was much more efficient than punching a wolf in the nose. Isn't Ace smart? Give the poor dear a clap guys! As for Luffy being abandoned, will you believe that Garp left him there for Ace to take care of? No matter how much I love him, that guy is kind of an asshole after all. Notice how both Sabo and Ace never got any real parental love in their lives? They're trying to fix that with Luffy :3 Ain't that sweet?

Also I noticed something. Whenever I post something it's bound to get a follow from some hopeful fanfictioner, but strangely enough not a favourite? I'm wondering if they clicked the wrong button or something (not that I don't love you please don't leave me). Luffy is definitely more than three years younger than Ace, just saying because I'm not too sure of their ages myself. In case anyone is confused; the author is confused too! Don't worry we're in the same boat! Actually that's bound to make some people worry, hmm. Also someone give me a prompt for a horror fic, I've always wanted to try a legit one without accidentally writing as much gore as I can. Thanks! :D

 **Talon out~!**


End file.
